Kuroobi is definitely better than Kuro. For one, he can tank and his skill can also stun too. Taking crews to battles definitely depend on your playing style, but I was on your shoe then I would pick Kuro, Jango, Gedatsu and Buggy

the reason is so simple, different players wants different crew setup, kuro has high speed therefore it can hit twice before anyone else on his skill turn. Kurobi has high dmg output due to his skill calculation exact same as morgan (1 hit KO irregardless your def once your hp is down to 44%) do the calculation yourself.

I woulld say kuro and kurobi on the same line so after 2 hits by kuro his hp would be near to 44%

Ok, now seiously, In normal combats, without A,S, or SS characters, use him as defense for the low HP members, he is very resistant. For A, S or SS character, put him in the line where the bos character is, to stun the boss